Sign flasher



April 1935. w. H. MARSHALL, JR 1,996,520

SIGN FLASHER Filed April 12, 1930 2 Sheets-Sheet 1 W/ZZ/AM h- NAPS/74411auioznuqs April 2, 1935. w MARSHALL, JR 1,996,520

SIGN FLASHER Filed April 12, 1930 2 Sheets-Sheet 2 m; Min

W/ZZ/A/V H MARSH/Ml Patented Apr. 2, 1935 UNITED STATES PATENT OFFICE 5Claims.

This invention relates to means for intermittently flashing an electricsign or the like.

One object of this invention is to provide an improved simplified devicefor supplying electric current to a sign or other electrical apparatusat regular intervals.

Other objects are to provide a device of this type operated by thecurrent which feeds the sign, and one which is readily adaptable for usewith either direct or alternating current; to reduce the moving parts toa minimum; to utilize an electric discharge device as a timing element,and to provide means for adjusting the duration of the current flow andof the intervals therebetween.

Other objects'relating to details of construction and assembly andeconomies of manufacture will appear hereinafter.

In the accompanying drawings:

Fig. 1 is a circuit diagram of the improved device arranged foroperation with direct current.

Fig. 2 is a circuit diagram arranged for operation with alternatingcurrent.

Fig. 3 is an elevation of the improved device showing the assemblythereof on a panel.

Referring to Fig. 1 of the drawings, the reference numerals I0 and I Idesignate, respectively, the positive and the negative input terminalswhich are adapted to be connected to a direct current supply line suchas is ordinarily used to illuminate signs. The main circuit passesdirectly from the terminals I0 and I I through the fixed and movablecontacts I2 and I3, respectively of a relay I4, to the output terminalsI5 which are connected to a sign, illustrated diagrammatically as aplurality of incandescent lamps I6.

The relay I4 is controlled through the medium of an electric dischargedevice I1, illustrated herein as a two element space discharge valvehaving a filament I8 and a plate IS. The filament circuit is connectedto the terminals I0 and II, the negative side directly and the positiveside through the contacts I2 and I3 of the relay and a resistance 20which reduces the line voltage to the correct value for proper operationof the valve IT. The positive side of the plate circuit passes throughthe windings of the relay I I to the positive input terminal III, thenegative side of the filament circuit completing the plate circuit. Avariable resistance 2| of any suitable type, illustrateddiagrammatically as a rheostat, is shunted across the windings of therelay I4, and a second rheostat 22 is placed in series with the relaywindings.

The movable contact I3 of the relay is normally held in circuit closingposition against the fixed contact I2 by gravity or a spring of anysuitable type. Preferably a condenser 23 is connected across thecontacts I2 and I3 to reduce sparking.

When the input terminals I0 and II are connected to the supply line,current flows through the relay contacts I2 and I3 to the sign lamps l6,and through the resistance 20 to the filament l8 of the valve. As thefilament heats up, space current begins to fiow to the plate I9 andthrough the windings of the relay I4. When the space current reaches apredetermined valve, the relay I4 retracts the movable contact l3 andbreaks the sign and filament circuits. The plate circuit, however, isunaffected by the relay and the space current continues to flow as thefilament cools until, at a pre-determined minimum value, the movablecontact I3 returns to circuit closing position and starts another cycleof operations. As shown in Fig. 3, the movable contact I3 of the relayis carried by a spring arm 24 connected to a pivoted armature 25. Thefixed contact I2 is carried by a screw 26 mounted on the base foradjustment toward or away from the relay magnets. The spring mounting ofthe contact I3 prevents flickering of the sign when the circuit isbroken, since the initial weak space currents, which may move thearmature slightly, do not interrupt the circuit.

The force required to hold the armature in raised position is less thanthe force required to initially lift the same, since the efiect of themagnetic flux varies inversely as the square of the distance. Thisdifierential measures the time during which the sign circuit is broken,and can be adjusted as desired by varying the position of the fixedcontact I2 with respect to the relay magnets. The rheostat 22 controlsthe resistance of the plate circuit, and the rheostat 2| controls theproportion of the space current which passes through the relay windings.Adjustment of these rheostats varies the length of time the sign circuitis closed and the interval between flashes. It will thus be seen thatthe timing of the device can be adjusted at will within wide limits.

Fig. 2 illustrates the circuit diagram of the device designed foroperation on alternating current. In this form the input terminals IDare connected through the relay contacts I2 and I3 to the sign lamps I6as in Fig. 1.

l8 of the valve I1 is fed at the proper voltage by the secondarywindings of a step-down transformer 21, the primary windings of whichare connected to the input terminals I0 through the contacts I2 and I3.The plate circuit passes The filament r vice is facilitated, since thethrough the windings of the relay [4 to one side of the supply line, andthrough a center tap on the secondary of the transformer 21 to the otherside of the supply line. Since the relay contacts l2 and I3 carryalternating current, the condenser 23 is connected across the relaywindings, instead of across the contacts.

In this form of the device, the valve H rectifies the space current toprovide direct current for operating the relay. In other respects theoperation is substantially identical with the operation of the directcurrent circuit illustrated in Fig. 1.

In manufacturing the devices the elements are preferably assembled on asuitable base or panel, as illustrated in Fig. 3. In the alternatingcurrent type the transformer 21 is installed in place of the resistance26 and the wiring rearranged slightly to accommodate the transformer andconnect the condenser 23 across the-relay windings. It will accordinglybe seen that the manufacture and assembly of the two types of thedeparts are largely interchangeable. I

An important feature of the invention resides in the fact that thedirect current circuit, as

shown in Fig. 1, may also be operated satisfactorily by alternatingcurrent, since the resistance 20 will reduce the voltage of eitherdirect 'or alternating current. Where alternating current 1s to beemployed exclusively, however, the

transformer is preferable, being less subject to heating and occupyingless space than the resistance. I g

Although the foregoing description is neces- V sarily of a detailedcharacterin order that the invention may be fully set forth, it is to beunderstood that various modifications and rearrangements of parts may beresorted to without departing from the spirit or scope of the inventionas defined in the following claims.

I claim:

1. In a sign flasher arranged to intermittently make and break theelectric current for a sign or the like and to be actuated by suchcurrent, the combination of a relay having windings and armaturecontrolled contacts, a sign load circuit passing through the contacts ofsaid relay, an electrical discharge device including a filament with anappreciable temperature lag and an' anode, a circuit for heating saidfilament passing :through the contacts of said relay, a circuit passingthrough the windings of said relay and between said filament and saidanode, all of said circuits being in parallel to receive current from asingle source.

2. In a sign flasher arranged to intermittently make and break theelectric current for a sign or the like and to be actuated by suchcurrent, the combination of a relay having windings and an armaturecontrolled circuit breaker, a sign load circuit passing through thecircuit breaker of said relay and adapted to be connected to a source ofelectric current, an electrical discharge device having an anode and afilament cathode with an appreciable temperature lag, a cathode heatingcircuit passing through the circuit breaker of said relay, and ananode-cathode circuit passing through the windings of said relay, and anadjustable resistor shunted across the windings of said relay to controlthe proportion of current in the anode-cathode circuit which passesthrough the windings of the relay.

3. In a sign flasher arranged to intermittently make and break theelectric current for a sign or the like and to be actuated by suchcurrent, the combination of a relay having windings and an armaturecontrolled circuit breaker, a sign load circuit passing through thecircuit breaker of said relay and adapted to be connected to a source ofelectric current, an electric discharge device having an anode and afilament cathode with an appreciable temperature lag, a cathode heatingcircuit passing through the circuit breakerof said relay, and ananode-cathode circuit passing through the windings of said relay, and anadjustable resistor in series with the windings of said relay forvarying the resistance thereof.

4. In a sign flasher arranged to intermittently make and break theelectric current for a sign or the like and to be actuated by suchcurrent, the combination of a direct current relay having windings andan armature controlled circuit breaker, a sign load circuit passingthrough the circuit breaker of said relay and adapted to be connected toa source of alternating current, an

electric discharge device having an anode and a filament cathode with anappreciable temperature lag, a circuit for heating said cathodeenergized by said source of alternating current in parallel with saidload circuit and passing through the circuit breaker of said relay andan anodecathode circuit passing through the windings of said relay andconnected to said source of alternating current to rectify the same toactuate said relay.

5. In a sign flasher arranged to intermittently make and break theelectric current fora sign or the like and to be actuated by suchcurrent, the

combination of a relay having windings and arma-

